Chemical mechanical polishing apparatuses (CMP apparatuses) are commonly used for the planarization of silicon wafers. In one type of CMP apparatus, a rotating pad is placed in contact with a rotating wafer and the pad is moved back and forth laterally relative to the rotating wafer. Additionally, a polishing slurry is forced into a gap between the wafer and the pad.
Wafers with low dielectric constants have relatively low mechanical strength and low adhesiveness. Unfortunately, existing CMP apparatuses are unable to apply relatively low pressure to the wafer. As a result thereof, the CMP apparatus can damage the wafer during the polishing process or can polish the wafer in a non uniform fashion.